Initiation fixture and an initiator assembly including the same

ABSTRACT

An initiator assembly ( 38 ) is factory-pre-assembled and comprises an initiation fixture ( 10 ) secured to a triggering device ( 40 ). The initiation fixture ( 10 ) comprises a unitary body, i.e., one without moving parts, and includes a bushing groove ( 18 ) to receive as an accessory an O-ring ( 64 ) to seal the device within the barrel ( 42 ) of the triggering device ( 40 ). A fuse/fixture sub-assembly ( 34 ) includes an initiation charge ( 30 ) disposed at the firing face ( 13   a ) and a signal-transmission fuse ( 22 ). The initiation fixture ( 110 ) may be a “universal” fixture having thereon optional external threads ( 36 ) and being otherwise dimensioned and configured to be received within either an internally threaded barrel ( 42 ) of a triggering device ( 40 ) or the barrel ( 42 ) of a triggering device which utilizes a fuse-holder cap ( 56 ). The initiator assembly ( 38 ) may include a spool ( 66 ) on which the signal-transmission tube ( 22 ) is wound.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of co-pending patentapplication Ser. No. 11/925,220, filed Oct. 26, 2007, which is acontinuation application of patent application Ser. No. 10/504,612, nowabandoned, which is a national stage filing of PCT/US03/04593, with aneffective Section 371 filing date of Feb. 17, 2005, which internationalapplication PCT/US03/04593 was filed on Feb. 14, 2003, and claims thebenefit of U.S. provisional application Ser. No. 60/357,464 filed Feb.15, 2002, all entitled “Initiation Fixture and an Initiator AssemblyIncluding the Same”.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention concerns an initiation fixture and initiatorassembly including the fixture. The initiator assembly facilitates theinitiation of a signal in a non-electric fuse such as asignal-transmission tube, e.g., shock tube. The initiator assemblycomprises a triggering device within which the initiation fixture isreceived. The triggering device initiates a signal within the fuse whichsignal serves to initiate a detonator or other signal-transmitting orexplosive device connected to the remote end of the fuse.

2. Related Art

U.S. Pat. No. 5,365,851 to Shaw, issued Nov. 22, 1994 and entitled“Initiator Device”, discloses (see FIGS. 1 and 2) an initiation fixture(16) for an impulse transmission tube comprising a sleeve (30) in whicha shock tube fuse (10) is received. A primer (percussion) cap (28) iscontained at one end of sleeve (30) in signal-transfer proximity to theinput end of the shock tube (10); the opposite (output) end of shocktube (10) has a detonator (14) secured thereto. An internal fence (32)establishes a touch hole (33) between the primer cap (28) and the inputend of the shock tube (10). A threaded retainer means (40) is movablyand rotatably disposed on the exterior surface of sleeve (30) to engageinternal threads formed in the end of barrel (22) of a triggering device(18). A first stop means (42) positions retainer (40) to properly locateprimer cap (28) for detonation by operation of a striking firing pin(20) of triggering device (18). An initiation fixture such as fixture(16) of Shaw U.S. Pat. No. 5,365,851 is usable only with a triggeringdevice having the interior threads needed to accommodate the exteriorthreads on the body of the device.

Triggering devices for use in firing initiation fixtures such as thosedisclosed by the above-described Shaw U.S. Pat. No. 5,365,851 (“the Shawpatent”), are usually comprised of a barrel containing at one end atrigger-operated, spring-loaded firing pin and having, at the other(output) end of the barrel, means for connecting the initiation fixtureto the barrel. Alternatively, the triggering device may contain apercussion cap and a structure for receiving and retaining the input endof a fuse in signal-transfer proximity to the percussion cap. In suchcase, the output end of the barrel of the triggering device usuallycontains a grommet or other tube-retaining structure within or alignedwith an aperture formed in a fuse-holder cap fitted over the output endof the barrel. The input end of the fuse is simply inserted into theaperture and advanced until it encounters a stop member, at which pointthe fuse is positioned within the barrel in signal-transfer proximity tothe initiation charge of the triggering device, provided only that theuser has taken care to fully insert the fuse. Such triggering devicesusually employ a safety mechanism and, once the safety mechanism isplaced in the armed position, the trigger of the device is operated sothat the firing pin strikes and initiates the initiation charge, therebyinitiating a signal in the fuse. As illustrated in the Shaw patent, theother (output) end of the fuse may be connected to a detonator;obviously, it may be connected to any other device which is operated bythe signal engendered in the fuse.

Whether an initiation fixture such as that of the Shaw patent isutilized, or whether the input end of the fuse is simply inserted into atriggering device containing its own initiation charge, assembly of theinitiator to the triggering device or insertion of the exposed end ofthe fuse is required in the field at the point of use. Such fieldassembly or insertion may be difficult because of weather conditions ordarkness, and exposes the necessarily open input end of the fuse and theinterior of the triggering device to the elements, with potentialadverse consequences on reliability of initiation.

SUMMARY OF THE INVENTION

Generally, in accordance with the present invention, there is providedan initiation fixture which is so dimensioned and configured that it maybe utilized in a factory-assembled or pre-assembled initiator assemblyof the invention. Such initiator assembly serves to initiate a signal ina fuse in order to detonate explosives and the like. The pre-assembledinitiator assembly avoids the necessity for field assembling aninitiation fixture or an exposed end of the fuse to a triggering device,as is required with the known prior art devices. Such field assembly isparticularly problematic in adverse weather conditions, at night, andmost particularly, in combat or clandestine use situations. Factory- orother pre-assembly of the initiator assembly facilitates a secure andweatherproof installation, and enables field use simply by operating thetriggering device.

The present invention also provides a “universal” initiation fixturewhich may be assembled either to a triggering device having an interiorthread to secure the fixture, to a triggering device using a fuse-holdercap.

Specifically, in accordance with the present invention, there isprovided an initiator assembly comprising a triggering device having abarrel comprising an output end and an interior surface, the barrelhaving disposed therein an internal positioning member and a firingmechanism comprising a firing pin. An initiation fixture is of unitaryconstruction so that no part thereof is movable relative to any otherpart thereof. The initiation fixture is secured to the triggering deviceand comprises: (i) a cylindrical body member having an external surface,an end face and a firing face, the body member being received within thebarrel of the triggering device at the output end thereof, (ii) alongitudinal internal passage extending through the body member, (iii)an external positioning member disposed on the external surface of thebody member and engaging the internal positioning member, therebypositioning the body member at a predetermined position within thebarrel, and (iv) an initiation charge disposed within the longitudinalinternal passage at the firing face of the body member and exposed tothe firing pin of the firing mechanism; and a signal-transmission fusesecured to and extending from the body member and having an input enddisposed in signal-transfer relation to the initiation charge, and anopposite output end.

In accordance with one aspect of the present invention, the internalpositioning member comprises an internal stop and the externalpositioning member comprises a shoulder, wherein the shoulder abuts theinternal stop thereby properly positioning the body member within thebarrel of the triggering device.

In accordance with another aspect of the present invention, the internalpositioning member comprises internal threads in the barrel and theexternal positioning member comprises external threads on the firingface of the body member, wherein the external threads of the body memberengage the internal threads of the triggering device to properlyposition the body member within the barrel of the triggering device.

In accordance with another aspect of the present invention, thetriggering device is mounted on a spool on which the signal-transmissionfuse is wound.

In accordance with another embodiment of the present invention, there isprovided an initiation fixture dimensioned and configured to be receivedwithin a barrel of a triggering device. The initiation fixture comprisesa cylindrical body member having an external surface, an end face and afiring face. The body member is dimensioned and configured to bereceived within a barrel of a triggering device. There is a longitudinalinternal passage which extends through the body member and a positioningmember disposed on the external surface of the body member dimensionedand configured to position the body member within the barrel. A well isformed in the body member at the firing face thereof and is dimensionedand configured to receive an initiation charge, the well being insignal-transfer communication with the longitudinal internal passage.The initiation fixture is of unitary construction, by which it is meantthat no part thereof is movable relative to any other part thereof.

In accordance with yet another embodiment of the present invention,there is provided an initiator assembly comprising a spool having asignal-transmission fuse wound thereon, the signal-transmission fusehaving an input end and an opposite, output end. A triggering device ismounted upon the spool, and has a barrel comprising an output end, thebarrel having a firing mechanism disposed therein. An initiation fixturecomprises a cylindrical body member received within the barrel of thetriggering device at the output end thereof, a longitudinal internalpassage which extends through the body member, and an initiation chargedisposed within the longitudinal internal passage of the body member andexposed to the firing mechanism. The input end of thesignal-transmission fuse is disposed within and secured to theinitiation fixture in signal-transfer relation to the initiation charge.

Other aspects of the present invention are revealed in the followingdescription and the appended drawings.

The term “signal” used in connection with a signal-transmission tubefuse means the detonating shock wave or deflagrating flame fronttransmitted along the tube interior and utilized to obtain a desiredeffect, such as to initiate a detonator, which may in turn initiate anexplosive charge.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of an initiation fixture in accordancewith one embodiment of the present invention having a shock tube fuseconnected thereto and an initiation charge mounted therein;

FIG. 1A is a view corresponding to that of FIG. 1, but with the shocktube fuse and initiation charge omitted;

FIG. 2 is a schematic cross-sectional view of an initiator assembly inaccordance with one embodiment of the present invention comprising atriggering device having the initiation fixture of FIGS. 1 and 1Asecured thereto;

FIG. 3 is a schematic cross-sectional view of an initiation fixture inaccordance with a second embodiment of the present invention;

FIG. 4 is a cross-sectional view of an initiation fixture in accordancewith a third embodiment of the present invention;

FIG. 5 is a plan view of an initiator assembly in accordance withanother embodiment of the present invention comprising a dual-barreltriggering device in which two of the initiation fixtures of FIG. 4 aremounted;

FIG. 6 is a side view of an initiator assembly in accordance with yetanother embodiment of the present invention comprising a spool on whicha fuse is wound and on which the triggering device is mounted; and

FIG. 7 is an end view of the initiator assembly of FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS THEREOF

One embodiment of an initiation fixture of the present invention isshown in FIGS. 1 and 1A. Initiation fixture 10 is a unitary, i.e.,one-piece, elongated and generally tubular structure comprised of acylindrical collet portion or body member 12 having a sleeve 14extending therefrom, and an external positioning member or shoulder 20extending circumferentially there-around. Shoulder 20, which isconfigured to bear against an internal stop member of a triggeringdevice to properly longitudinally position the initiation fixture 10within the de-vice, also serves to define a nose portion 13 of bodymember 12. Nose portion 13 terminates in a firing face 13 a. Alongitudinal internal passage 11 extends (FIG. 1A) through fixture 10from a first end 10 a thereof through sleeve 14 to firing face 13 a. Atouch hole 10 b and an initiation charge well 10 c (FIG. 1A) are formedin internal passage 11 within nose portion 13. The interiorconfiguration of fixture 10 is substantially the same as the interior ofthe fixture shown in the Shaw patent, discussed above. Body member 12has a rounded shoulder 16 that faces towards first end 10 a of fixture10, and a circumferential bushing groove 18 (FIG. 1A) within which asealing member comprising an O-ring 64 (FIG. 1) is seated. The sealingmember is not a part of a unitary initiation fixture, but rather anaccessory therefor. Initiation fixture 10 may be made of any suitablematerial. There is included within the purview of the present inventionan initiation fixture, such as initiation fixture 10, which is of“unitary” construction, that is, it is an integral piece with no partswhich are movable relative to each other. A preferred form ofconstruction is to fabricate initiation fixture 10 by machining a singlelength of metal rod, such as an aluminum rod.

The fuses with which the fixture of this invention may be used includedetonating cord (in which case a remotely actuated triggering mechanismis used) and, more usually, signal-transmission tubes. Asignal-transmission tube may be any detonating or deflagrating (lowvelocity) signal-transmission tube or fuse which can carry a detonatingsignal or deflagrating signal along its interior. Such detonatingsignal-transmission tubes are commonly referred to as “shock tube” andmay be of the type disclosed in Persson U.S. Pat. No. 3,590,739 orThureson et al U.S. Pat. No. 4,607,573. A deflagratingsignal-transmission tube may be of the type disclosed in Thureson U.S.Pat. No. 4,757,764. Such impulse transmission tubes comprise flexiblehollow plastic tubes having an interior coating of a reactive materialcapable of carrying a detonating or deflagrating signal.

In the embodiment illustrated in FIG. 1, a signal-transmission fuse isprovided by a shock tube fuse 22, one end of which is received withinsleeve 14 of fixture 10 and terminates in input end 22 a of fuse 22. Anisolation member 24 is interposed between input end 22 a of fuse 22 andan initiation charge 30, which may comprise a known type ofpercussion-sensitive charge. For example, initiation charge 30 may be aprimer cap such as an M42C1 primer cap containing a nominal loading of0.34 grams of a lead styphnate-tetracene, non-corrosive-type primingmixture. As is well-known in the art, isolation member 24 serves todisperse static electricity which may accumulate within or on shock tubefuse 22 to thereby avoid electrostatic discharge to initiation charge30. A fuse bushing 26 surrounds fuse 22 which is secured in sleeve 14 bycrimping sleeve 14 to form crimp 28. Input end 22 a contacts isolationmember 24, which is preferably configured to diverge from its centralmembrane 24 a in the direction towards first end 10 a to enableisolation member 24 to receive therein the ends of fuses of varyingdiameters. One type of fuse is shock tube, having an outside diameter inthe range of about 0.085 inch (about 2.2 mm) to about 0.118 inch (about3 mm) or more.

The touch hole 10 b between initiation charge well 10 c (FIG. 1A) andfuse 22 within sleeve 14 is formed by an internal fence 32 in fixture10. The touch hole 10 b provides a conduit by which the output ofinitiation charge 30 enters sleeve 14, penetrating the central membrane24 a of isolation member 24 and initiating the reactive material in fuse22.

Initiation fixture 10 with initiation charge 30 and signal-transmissionfuse 22 mounted therein provides a fuse/fixture sub-assembly 34. Adetonator (not shown in FIG. 1) or other explosive or device may beconnected to the output end (not shown) of fuse 22 to be acted upon bythe signal to be generated in fuse 22.

FIG. 2 shows an initiator assembly 38 in accordance with one embodimentof the present invention in which the fuse/fixture sub-assembly 34 ofFIG. 1 is secured in a triggering device 40. As part of the assembly oftriggering device 40, sleeve 14 of fixture 10 is passed through anaperture 58 in a fuse-holder cap 56 and fuse 22 is then inserted throughsleeve 14 which is crimped thereon as described above. The illustratedtriggering device 40 is standard United States Army issue designated asan M81 triggering device. Triggering device 40 comprises a housing orbarrel 42 which is generally tubular and which is configured to receiveinitiation fixture 10 of sub-assembly 34 at the output end 42 a thereof.The interior bore of output end 42 a of barrel 42 is slightly tapered toflare outwardly, as seen in FIG. 2. Barrel 42 also encloses aspring-loaded firing mechanism comprising a firing pin 44 and a spring46, which are shown in FIG. 2 in the pre-firing configuration, i.e.,with spring 46 compressed and ready to drive firing pin 44 forward tostrike initiation charge 30. A pull rod 48 extends from the barrel 42and engages spring 46 to hold it in its compressed condition. A pullring 50 is connected to the end of pull rod 48, which projects outwardlyof a threaded top cap 52 which encloses the breech end 42 b of thebarrel 42 from which pull rod 48 extends. Pull ring 50 is rotatableabout the end of pull rod 48 and is shown in FIG. 2 rotated towards thebarrel 42. For safety purposes, pull rod 48 and top cap 52 areperforated to permit a cotter pin 54 to be inserted therethrough toprovide a safety mechanism to prevent the inadvertent withdrawal of pullrod 48 from barrel 42. The structure and function of triggering devicessuch as triggering device 40 are well known to those skilled in the art,and therefore a more detailed description of such structure and functionis not necessary. It suffices to say that when the user desires toinitiate the signal in the signal-transmission fuse 22, cotter pin 54 isremoved and the pull ring 50 is pulled to release the compressed spring46 which drives firing pin 44 forward to strike and initiate initiationcharge 30, which initiates a signal in signal transmission fuse 22.

The fuse-holder cap 56 is mounted on the output end 42 a of barrel 42 bythreaded engagement with external threads (unnumbered) adjacent theoutput end 42 a. The interior of fuse-holder cap 56 includes a conicalbearing surface 60. As fuse-holder cap 56 is threaded onto barrel 42,bearing surface 60 bears against rounded shoulder 16 of fixture 10,driving fixture/fuse assembly 34 into triggering device 40. Preferably,barrel 42 of device 40 includes an internal positioning member orinternal stop 62 that engages shoulder 20 (see FIG. 1A) of fixture 10 sothat initiation charge 30 is properly positioned in barrel 42 relativeto firing pin 44.

The fixture/fuse sub-assembly 34 includes an O-ring 64 retained inbushing groove 18 (FIG. 1A). O-ring 64 is dimensioned and configured toform a water- and weather-tight seal between fixture 10 and the interiorof barrel 42. The interior of barrel 42, including initiation charge 30,is thus protected against contamination from moisture or othercontaminants that might otherwise enter barrel 42 through aperture 58.

In an alternative embodiment of the invention, the initiation fixturemay be configured to conform to the tapered interior bore of output end42 a of barrel 42. Specifically, as shown in FIG. 3, a proximal portion15 of body member 12′ of a fixture 10′ may be tapered to flare outwardlyto conform to the flared interior bore of output end 42 a of barrel 42(FIG. 2). Body member 12′ includes a nose portion 13′ of uniformdiameter which extends into barrel 42 (FIG. 2) beyond the taperedsurface. The tapered construction of body member 12′ serves to fix thelongitudinal position of fixture 10′ in the barrel 42 of a triggeringdevice 40. Body member 12′ has a longitudinal internal passage 11′, afiring face 13 a′, a sleeve 14′, a bushing groove 18′, and an initiationcharge well 10 c′ which correspond to and serve the same functions asdescribed in connection with the initiation fixture 10 of FIGS. 1 and1A, and which therefore need not be further described.

Referring now to FIG. 4, there is shown a fixture/fuse sub-assembly 134comprising fixture 110, which is similar to fixture 10 of FIG. 1 exceptthat it contains external threads 36 on nose portion 113 of body member112. Fixture 110 has a shoulder 120, and a signal-transmission fuse 122is received within sleeve 114. That portion of fuse 122 received withinsleeve 114 is encased within a fuse bushing (not shown). The externalthreads 36 serve to engage internal threads disposed at one end of atriggering device to position and retain body member 112 in the barrelof a triggering device, not shown in FIG. 4. Initiation fixture 110 is a“universal” fixture as it may be secured to the barrel of a triggeringdevice having internal threads or to the barrel of a triggering deviceusing a fuse-holder cap, such as fuse-holder cap 56 in FIG. 2, to engagerounded shoulder 116. In such case, shoulder 120 contacts a stop memberwithin the barrel of the triggering device to assure proper positioning.

Referring now to FIG. 5, there are shown two of the fixture/fusesub-assembly 134 of FIG. 4 secured in a dual-barrel triggering device140. The illustrated triggering device 140 is used by the United StatesArmy under the designation MK54. The triggering device 140 comprises twobarrels 142 a and 142 b which are generally tubular and have internalthreads which are configured to receive fixture/fuse sub-assemblies 134therein. Barrels 142 a and 142 b also enclose firing mechanismscomprising firing pins 144 a and 144 b and firing springs (not shown).Structure 144 comprises a safety-and-trigger operating structure wellknown in the art, and therefore the structure and function need not befurther described. For use, the user removes a safety pin 166 andpresses a trigger 168 to release the firing pins 144 a and 144 b.

Referring now to FIGS. 6 and 7, there is shown an initiator assembly 80comprising triggering device 40, having fixture/fuse sub-assembly 34connected thereto as shown in FIG. 2, mounted upon a spool 66 which hasa signal-transmission fuse 22 wound thereon. The triggering device 40 ismounted onto a flange 66 a of spool 66 and is secured in place by afastener 70. The fastener 70 is attached to pull ring 50 of triggeringdevice 40. Triggering device 40 is secured to spool 66 by a retainingstrap 68 on the flange 66 a of spool 66. A protective sleeve 78 covers aportion of signal-transmission fuse 22 that passes through opening 79 inthe flange 66 a of spool 66.

Flexible retaining strap 68 is secured at one end to the flange 66 a ofspool 66 so that upon removing or rupturing fastener 70, triggeringdevice 40 can quickly be removed from spool 66 by moving it in thedirection of the arrow D in FIG. 6.

The initiator assembly 80 has a detonator 74 secured to an output end 22b (FIG. 7) of the signal-transmission fuse 22 and contained within aconnector bunch block 72. Connector bunch block 72 serves, as is wellknown to those skilled in the art, to receive one or more, usually aplurality, of receptor signal-transmission fuses which are positioned insignal-transfer proximity to detonator 74 by placing the receptorsignal-transmission tubes within connector bunch block 72 and lockingthem in place by closing flap 75 a. Flap 75 b is closed to help securedetonator 74 in place. A retaining strap 76 serves to secure connectorbunch block 72 in place for storage and shipment. Obviously, anysuitable connector block may be used, or the connector block may beomitted and detonator 74 left free to be inserted into an explosivecharge or other device.

In use, after severing or rupturing strap 76, connector bunch block 72is removed from spool 66 and receptor signal-transmission tubes (notshown) are passed through bunch block 72 in signal transfer proximity todetonator 74. Flaps 75 a and 75 b of bunch block 72 are then closed tosecure the receptor signal-transmission tubes and detonator 74 in placewithin connector bunch block 72. With that installation complete andbunch block 72 fixed in place, the user carries spool 66 to a remotelocation, playing out any required length of signal-trans-mission tube22 up to the capacity of tube 22 stored on spool 66. When the user isready to initiate the signal, triggering device 40 is removed from spool66 by moving it in the direction shown by arrow D, any safety pin orother safety device (not shown in FIG. 6) is removed or placed in thearmed position, and pull ring 50 is pulled to initiate the firingsequence.

When the fixture is mounted on the end of a fuse and has an initiationcharge therein, the resulting combination is a fixture/fuse sub-assemblythat can be easily secured into a variety of triggering devices such asU.S. Army M60 and MK54 devices.

While the invention has been described with reference to specificembodiments thereof, it will be appreciated that numerous othervariations may be made to the illustrated specific embodiments whichvariations nonetheless lie within the spirit and the scope of theinvention.

1. An initiator assembly comprising: (a) a triggering device having abarrel comprising an output end and an interior surface, the barrelhaving disposed therein an internal positioning member and a firingmechanism comprising a firing pin; (b) an initiation fixture which is ofunitary construction whereby no part thereof defined as (i) through (iv)below is movable relative to any other part (i) through (iv) thereof,and the initiation fixture is secured to the triggering device andcomprises: (i) a cylindrical body member having an external surface anda nose portion terminating in a firing face, the body member beingconfigured to be received longitudinally within the barrel of thetriggering device at the output end thereof, (ii) a longitudinalinternal passage extending through the body member, (iii) an externalpositioning member disposed on the external surface of the body memberand engaging the internal positioning member, thereby positioning thebody member at a predetermined position within the barrel, and (iv) awell formed in the body member at the firing face thereof anddimensioned and configured to receive an initiation charge, the wellbeing in signal-transfer communication with the longitudinal internalpassage; and (c) a signal-transmission fuse secured to and extendingfrom the body member and having an input end disposed in signal-transferrelation to the initiation charge, and an opposite output end.
 2. Theassembly of claim 1, wherein the internal positioning member comprisesan internal stop and the external positioning member comprises ashoulder which is dimensioned and configured to abut the internal stop.3. The assembly of claim 1 or claim 11, wherein the initiation fixturefurther comprises a sealing member disposed circumferentially about thebody member and dimensioned and configured to engage the interiorsurface of the barrel to form a seal therewith.
 4. The assembly of claim1 or claim 11, wherein the triggering device further comprises afuse-holder cap disposed at the output end of the barrel and havingtherein an aperture through which the signal-transmission fuse passes.5. The assembly of claim 4, wherein the end face of the body member isdimensioned and configured to be engaged by the fuse-holder cap toretain the body member within the barrel.
 6. The assembly of claim 1 orclaim 11, wherein the initiation fixture further comprises a sleeveextending from the end face of the body member and through which thesignal-transmission fuse passes.
 7. The assembly of claim 6, wherein thetriggering device further comprises a fuse-holder cap disposed at theoutput end of the barrel, and having therein an aperture through whichthe sleeve of the initiation fixture extends.
 8. The assembly of claim 1or claim 11, wherein the triggering device is mounted on a spool onwhich the signal-transmission fuse is wound.
 9. The assembly of claim 1or claim 11, wherein the output end of the signal-transmission fuse isreceived within a detonator.
 10. The assembly of claim 9, wherein thedetonator is positioned within a connector block dimensioned andconfigured to receive a plurality of signal-transmission lines therein.11. An initiator assembly comprising: (a) a triggering device having abarrel comprising an output end and an interior surface, the barrelhaving disposed therein an internal positioning member and a firingmechanism comprising a firing pin; (b) an initiation fixture which is ofunitary construction whereby no part thereof defined as (i) through (iv)below is movable relative to any other part (i) through (iv) thereof,and the initiation fixture is secured to the triggering device andcomprises: (i) a cylindrical body member having an external surface anda nose portion terminating in a firing face, the body member beingconfigured to be received longitudinally within the barrel of thetriggering device at the output end thereof, (ii) a longitudinalinternal passage extending through the body member, (iii) an externalpositioning member disposed on the external surface of the body memberand engaging the internal positioning member, thereby positioning thebody member at a predetermined position within the barrel, and (iv) awell formed in the body member at the firing face thereof and insignal-transfer communication with the longitudinal internal passage;and (c) an initiation charge disposed within the well at the firing faceof the body member and exposed to the firing pin of the firingmechanism, and a signal-transmission fuse secured to and extending fromthe body member and having an input end disposed in signal-transferrelation to the initiation charge, and an opposite output end.